The present invention relates to a traffic management system and a traffic management method for managing in a road network the vehicle traffic formed on a physical layer by a plurality of vehicles which travel along a plurality of road sections of the road network and pass certain road points located at the road sections of the road network.
In particular, the present invention addresses the problems of how an effective traffic management system can be devised, which provides more intelligence for an efficient traffic management, regarding the traffic management aspect of merely effectively monitoring the existing traffic as well as the traffic management aspect of effectively controlling the traffic. For example an effective setting of traffic control signs, an effective route-planning by not only considering traffic jams and congestions but also road charging, the gathering of statistical data from existing traffic, the prevention of dangerous or generally unwanted traffic situations by changing traffic signs in case of dangerous traffic situations as well as the achieving of desired traffic situations should be possible. Furthermore, the traffic control system of the invention should be easy to operate, user-friendly and low-cost.
With the ever increasing demands to growing mobility, the automobile industry has developed the vehicular technology to such a degree that now a range of products for various purposes and missions are available and an adequate cost-benefit balance can be provided for every application. On the other hand, the growing demand to mobility has caused the need for the public authorities to extend the old network of roads and highways to cope with the ever increasing traffic.
However, the expansion of the network and the related infrastructure has been notably smaller than the increase of the number of vehicles. That is, the existing road networks cannot cope with the ever increasing traffic and this unbalance causes traffic situations with congestions and accidents. Other consequences are an increased fuel consumption, general waste of time, the environmental pollution, noise, stress and other discomfort for humans. Apart from not very effective counter measures to stop the growth of the traffic, such as increasing fuel cost and higher taxation, there are no effective counter measures with which the gap between the mobility demand and the necessary infra-structural means can be bridged which leads to higher transportation costs, waste of fuel and time, environmental problems as well as a lower safety level.
These circumstances have resulted in a high demand for effective traffic control measures to avoid a collapse of a complete transportation system. Therefore, it is now generally accepted that a wide range of more global and integrated measures have to be identified and implemented together with a systematic approach. In particular, the demands to a new traffic control system are to balance the demand and offer within the whole transport system, i.e. to manage the transport resources (roads, traffic signs etc., traffic flow control) to be optimally adapted to the traffic situations and demands (i.e. number of vehicles, type of vehicles, desired destination etc.).
At present several new approaches for more effective traffic (congestion) control systems are tested, in particular in the Netherlands. However, most of the traffic control systems existing today are of a rather static nature. Only some of them use changeable traffic signs depending on the time of day or the actual traffic situation, e.g. a variable speed limit on a motorway depending on the congestion condition. Thus, only a few traffic signs (such as parking permission, speed limit, use of one or two lanes on a road) may have a different meaning depending on the time of day or the day of the month and they are not controlled in an integrated manner, i.e. they do not take into account a traffic situation which exists elsewhere (away from the road section where e.g. the particular variable speed limit is arranged) but which may also have an influence on the road section considered.
For monitoring purposes certain highways are on a limited scale equipped with sensors, which measure the traffic flow and provide information in the traffic loads or bad weather conditions in order to change some traffic signs mounted above the highway to indicate dangerous situations.
However, this change of warning signs like bad weather conditions, accident and congestion only change the traffic signs on the highways in a very limited scale, namely on a rather local scale rather than being able to more globally control the complete traffic flow for example in an integrated manner in a whole area of for example one or two local areas, e.g. a complete city.
Intelligent Speed Control (Intelligente Snelheidsadaptor)
In an intelligent speed control system, which is currently being tested in the Netherlands the aim is to control the maximum speed by means of broadcasting systems. The basic idea here is to have a system broadcast the maximum speed in a certain area. Each vehicle is equipped with a traffic information unit, e.g. a speed sensor, which detects the maximum speed broadcast from the speed broadcasting system of the system. The speed broadcasting system receives information from a traffic information system and broadcasts the respective appropriate speed in each area. In this field trial each vehicle has a speed sensor, which detects the broadcast maximum speed and informs a speed control system (similar to the well-known cruise-control) inside the vehicle about the determined speed. As in the cruise control system of course there is the possibility to overrule the system in certain cases such as emergency situations etc.
In this system each vehicle needs to be equipped with the sensor and the speed control system or a system is needed to be able to track each vehicle, which drove with too high speed. For example, a GPS system may be used for tracking the speed of each vehicle or the vehicle itself records (like a flight-recorder) all travel details and reports this information back to the system. In such a case a system like a tag billing system (rekening-rijden) can be established.
Tag Billing System (Rekening-Rijden)
In the Netherlands also field trials are performed to have each vehicle equipped with an identification tag connected to the number plate. At certain road points along the roads stations may be arranged which sense the passing of a vehicle with an identification tag. Thus, it will be possible to charge the persons who have used that road. Similar to the motorway charging system for example employed in Italy where a sensing apparatus senses the passing of a vehicle through a toll station, the system in the Netherlands is based on a more individual charging because each tag will in a unique manner identify the passing vehicle.
The whole system, i.e. determining the vehicles which use a certain road and the generation of the bill can be automated to a large extent and it may be used to control access to busy city centres etc.
Route-Planners
Existing route-planners (mostly employed in vehicle navigation systems) are also static and do not take into account road-blocks, congestions, i.e. the actual traffic situation. On-board-computers inform the driver about the shortest route to the corresponding destination, but these are very static and updates are costly (due to the fact that the information is stored on a local disc in the on-board-computer). Such route-planners are only capable of planning a route for a single individual vehicle dependent on its desired vehicle destination without considering current or possibly foreseeable future traffic conditions.
Fleet-Managing Systems
Fleet-management companies are able to track their vehicles, bikes etc. and to determine the nearest participant to a corresponding desired destination (e.g. a customer). Such systems are based on GPS information or on the usage of radio links. However, the nearest participant is only based on the actual distance, i.e. it is not possible to take into account the actual traffic situation, which means that the actual time needed to approach the destination could be shorter and/or cheaper when using another (longer distance) route.
However, with the advent of modern telecommunication technologies, such as mobile communication networks, already intrinsically allowing the free movement and mobility of mobile radios, many governments like the Dutch Ministry of xe2x80x9cTraffic Planningxe2x80x9d are now increasing efforts to use such telecommunication technologies for an efficient traffic control and for the prevention of accidents and traffic congestions.
Mobile Radio Communication Systems
One of the characteristic features of modern mobile radio communication systems such as GSM (Global System of Mobile communications, GPRS (General Packet Routing System) and UMTS (Universal Mobile Telephone System) is that it is possible to track the location and direction of a mobile station in the mobile radio communication network.
When a GPS (Global Positioning System) system is incorporated into the mobile radio station, the accuracy can be improved. With this system it is possible to also determine the speed of the vehicle in order to be able to know whether the vehicles in a certain area or on a certain road are driving slower than usual which would mean (of course depending on the type of road) that there is a traffic congestion due to some reason.
The possibility to determine the location and speed of a vehicle is an attractive feature for a traffic control system and such systems are currently being tested in the Netherlands to advise vehicles to take another route in case of a congestion. In this system, a central office is informed when a certain amount of vehicles is slower than usual (e.g. the mobile radio stations of the vehicles report their speed to the central office) upon which a person in the central office manually checks for alternative routes. When such an alternative route is found a SMS message (Short Message System) is broadcasted to all the mobile stations (i.e. all the vehicles) in a corresponding region, to advise them to select another route.
By the use of mobile radio communication systems such as GSM, GPRS or UMTS the movement of a mobile station from one cell (or a sector) to another cell (or a sector) can be tracked with high accuracy such that detailed information about the location, speed and movement direction of the mobile station and therefore of the vehicle can be obtained to provide more up to date and non-static information about the traffic flow.
However, in traffic control systems using these features of the mobile communication network, the mobile communication network is only used for determining the location and for transmitting corresponding information to a central office, such that still a full modelling of the traffic flow is not possible because the control, e.g. the diversion, of traffic only takes place on a localized basis rather than on a global basis.
Disadvantages of the Existing Traffic Control Systems
As can be seen from the above description, the traffic control systems, which are currently being tested and implemented still suffer from a number of problems, for example:
1. With the ever increasing traffic amount in the future it will basically not be possible any more to provide an efficient traffic control merely based on static or localized mechanisms such that there is a need for a more global monitoring and control of the traffic flow.
2. The existing route-planners are relatively static and updates of the information in the on-board-computers are costly. Furthermore, upgrading is necessary, whenever a road is added, removed or changed (basically the problem is caused by the fact that the service is in the vehicle itself and not in the networks). Furthermore, existing route planners in particular only perform a route planning by considering the desired vehicle destination of a single vehicle, such that the interaction and the changing of the traffic flow dependent on an interaction of the individually planned routes of several vehicles can not be taken into account for the route planning.
3. Existing fleet-management systems are also static and only take into account the distances but not the actual traffic situation.
4. The existing traffic control systems are local traffic flow optimisations, i.e. more global circumstances are not taken into account. Systems on highways, which indicate the maximum or recommended speed (as explained above), only try to prevent traffic jams on that specific part of the highway. Even systems, which make sure that all traffic lights are green (xe2x80x9cgreen-phasexe2x80x9d) when having a specific speed are just local optimisations and do not take into account global traffic circumstances.
5. With current systems it is not possible (at least not automated) to get statistical information about the traffic in order to be used as input to traffic planning systems.
Therefore, there is a need for developing more efficient traffic management systems, which actually take into account, on a global basis, the traffic flow conditions. Furthermore, there is a need for developing traffic control systems which also act in a feedback manner in order to control traffic signs or vehicles on a dynamic basis.
As explained above, current traffic control systems are either based on localized considerations of the traffic flow, do not take into account dynamic changing traffic conditions, do not provide an accurate monitoring of the traffic flow, and in particular do not allow to make any precise predictions how the traffic flow is going to change and how the traffic flow should be controlled in order to avoid dangerous foreseeable bad traffic conditions.
Therefore, the object of the present invention is the provision of
a traffic management system and a traffic management method which perform a more efficient traffic management.
This object is solved by a traffic management system according to claim 1, characterized in that a traffic management system for managing in a road network the vehicle traffic formed, on a physical layer, by a plurality of vehicles travelling along a plurality of road sections of the road network and a plurality of road points located at said road sections of the road network, comprising: a packet switched control network on a traffic control layer in which the packet traffic constituted by a plurality of packets being routed along a plurality of packet routing links (PRL1-PRLm) is controlled by a plurality of packet control units located at said packet routing links; wherein
said packet switched control network on the traffic control layer is configured in such a way that packet routing links correspond to roads sections; packet control units correspond to road points; and each packet routed along a respective packet routing link corresponds to or simulates at least one vehicle travelling on a corresponding road section; wherein
said packet control units are adapted to control the packets on a respective packet routing link in the traffic control layer to correspond to or simulate a respective vehicle on a corresponding road section on the physical layer.
Furthermore, this object is solved by a traffic management method according to claim 26 characterized in that a method for managing in a road network the vehicle traffic formed, on a physical layer, by a plurality of vehicles travelling along a plurality of road sections of the road network and a plurality of road points located at said road sections of the road network comprising the following steps: configuring a packet switched control network on a traffic control layer including a plurality of packet routing links and a plurality of packet control units located at said packet routing links such that packet routing links correspond to roads sections and packet control units correspond to road points (ICP1-ICPn); and controlling the packet control units for routing the packets along respective packet routing links such that they correspond to or simulate at least one vehicle travelling on a corresponding road section.
Furthermore, this object is solved by a computer program product according to claim 30 characterized in that a computer program product stored on a computer readable storage medium comprising code means adapted to carry out the method steps a) and b) of claim 29.
Advantageous Embodiments
Further advantageous embodiments and improvements of the invention are listed in the dependent claims. Hereinafter, the invention will be described with reference to its advantageous embodiments and with respect to what is currently considered by the inventors to be the best mode of the invention.
Furthermore, it should be noted that the invention can be modified and varied in many respects on the basis of the teachings contained herein. For example, the invention may comprise embodiments, which are a result of combining features and steps which have been separately described and listed in the claims, drawings and in the description.